Solid-state imaging element and camera system

Abstract

Disclosed herein is a solid-state imaging element including a pixel unit configured to include a plurality of pixels arranged in a matrix and a pixel signal readout unit configured to include an analog-digital conversion unit that carries out analog-digital conversion of a pixel signal read out from the pixel unit. Each one of the pixels in the pixel unit includes a plurality of divided pixels arising from division into regions different from each other in optical sensitivity or a charge accumulation amount. The pixel signal readout unit reads out divided-pixel signals of the divided pixels in the pixel. The analog-digital conversion unit carries out analog-digital conversion of the divided-pixel signals that are read out and adds the divided-pixel signals to each other to obtain a pixel signal of one pixel.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a solid-state imaging element typified by a CCD and a CMOS image sensor, and a camera system.[0003]2. Description of the Related Art[0004]It is desired to realize a wide dynamic range solid-state imaging element by which even details can be so imaged that high-luminance information does not collapse and low-luminance part of the subject image does not become too black even in photographing against light such as light of car headlights, illumination light of a ball game ground, or sunlight.[0005]Under such circumstances, regarding a solid-state imaging element such as a CCD, techniques for enlarging the dynamic range are disclosed in e.g. Japanese Patent No. 2125710, Japanese Patent Laid-Open No. Hei 3-117281, Japanese Patent Laid-Open No. Hei 9-205589, and Japanese Patent Laid-Open No. 2004-320119 (Hereinafter, Patent Document 1, Patent Document 2, Patent Document 3, and Patent Document ...

AI Technical Summary

Benefits of technology

This approach enables a wide dynamic range imaging system with high sensitivity at low light levels and reduced sensitivity at high light levels, minimizing saturation and enhancing signal-to-noise ratio, while eliminating the need for external memory and maintaining high resolution without increased processing complexity.

Problems solved by technology

However, in the case of the above-described divided-pixel addition, an invalid region (dead space) that does not directly contribute to photo-sensing exists in terms of signal processing differently from a pixel having the area equal to the total of the areas of the divided pixels.

This causes e.g. a problem that the saturation value varies and the breakpoint position also varies.

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